This has just happened to me, one day I was flying fine, the next I was not able to connect. Sure enough the cable to the micro USB port on the MA controller was very loose and would not fit securely. By pressing tightly and holding the cable in I could regain connection, but as soon as letting pressure go the connection is gone.
How do I possibly fix this without having to send the drone in to DJI? I want to avoid that at all costs
How old is you MA? If it's still under warranty, then I would send it in.